Fastener



Patented Nov. 30, 1943 FASTENER Marvin c. Herm, muismat-111e, N. Y.,assimiy to Bell'Aircraft Corporation, Buffalo. N. Y.v

Application September 5, 1941, Serial No. 409,694 I (ci. 24- zzn Thisinvention relates to fasteners, and moreV particularly to a new andimproved device' for quickly and detachablyfastening separate elementssuch as sheet metal elements in connectionwith airplane cowling, or thelike.

One object of the invention is to provide a device of the characterdescribed having two cooperating members adapted to be brought into andout of locked relation in an improved mananer.- Other objects andadvantages of the in- 'vention will appear in the specicationhereinafter.

In the drawing:

Fig. 1 is a top plan of a fastener of the invention mounted upon sheetmetal structure;

Fig. 2 is a section taken substantially 'along line II-II of Fig. l,-showing cooperative portions vof the fastener device locked ininterengaged condition; and 4 Fig. 3 is a section taken substantiallyalong line lII--III of Fig. 2.

The -invention is illustrated in conjunction with upper and lower sheetmetal members I0 and I2, respectively. 'I'he lowerA- sheet member I2 isillustrated as carrying one of the cooptained within'the vbody of thenut I4 by a turned ange portion I2 which is formed at the extreme lowerend of thebody of the Anut I4.

The anchor plate 30 is* apertured at 34 so as to' provide an air ventdevice whereby the bear- Y ing plate and locking disc assembly may befree to move vertically within the bcdy of the nut erating portions ofthe fastening device which will be hereinafterreferred to generally asthe -nut or cylindrical retainer I4, and it will be noted that the sheet`metal member'l2 is aainularly apertured at I6 so as to 'receive the up-I4 without interference from pneumatic pres,- sure forces. 'Ihe upperportion of the body of the nut I4 is centrally bored and tapped asindicated at 36 for screwthreaded engagement with a threaded shankportion 38 of the screw member 4|! of the device. The screw member 40 isformed with a head portion of conical shape at its under surface so asto be adapted to engage in snug fitting -relation within a tapered orcountersunk type portion 44 of the sheet member I0.

'I'he upper face portion of the nut I4 is countersunk as at 45 so as tocomplement the tapered form of Athe }.sheet metal portion 44 whenbrought into engagement therewith. Thus, the screw 40 Y is adapted to'vbeinserted through the sheet metal member I0 in such manner as to havethe head portion 42 thereof disposed in ilush relation within thecountersunk portion 44 of the sheet member I0: and when in this positionthescrew 40 is adapted to be screwed into the threaded per end portionof the nut or cylindrical retainer I4. 'I'he nut or cylindrical retainerI4 is riveted upon the sheet I2 at its remote upper end portionasindicated at I8, andthus the nut is rigidly mounted upon the sheet.

'I'he lower portion of the body of the nut I4 is bored as at I8`to formanaxially yextending chamber to receive in vertically slidable .rela-'tion therein a. locking disc 2|! which is formed with a plurality ofspaced' radially extending members Iii- I2 into rmly xed relation. AVsplit spring washer 46 is applied to the upper shank portion of thescrew subsequent to assembly of the screw upon the sheet III so asslotted as .at 48 for'engagement therewith by the bla'ie of ascrewdriver or the like, and the screw ears 22 for splined connectionwith correspond.-

ing vertically grooved portions l24 of the nut or cylindrical retainerI4. Thus, the locking disc zn is free to oat vertically within the bodyof thenut I4 but is'prevented from rotating vtherewithin by reason ofthe splinel connection referred to. A bearing plate 26 is disposedtoabut the screw and pin. The pin 50 and the ,screw 'against the bottomface of the locking disc, 2'0;

bear at one of its ends upwardly against the bear- 40 is centrally bored so as to be adapted to'carry therewith a icontrol pin- 50 intelescopic relation therewithin. The control pin. 50 and the screw 40are shouldered as at 52 so as to pre# vent kdisplacement of thepin 50outwardly of the screw 4i? beyond a flush-end position and' at itsopposite end the boreof the screw40 is reduced in diameter to preventdisassembly of against thebearing plate 26, and is n rmally-maintaineebythe aetidn yof the spring za m ing plate 26 and downwardlyat its YotherY end V against an anchor plate 3U. A'I'he anchor plate'raised or. end-hush position with respect to the upper face of the screw40. However, it will 'be understood that'upon insertion of avscrewdriver or other sintomo too1within the dotted portion 48 of thescrew head, the tool will press the pin 5I) downwardly against theaction of the spring 28 so as to press the bearing plate 26 and lockingdisc'20 downwardly for a distance equal to the depth of the screwdriverslot 48. i The locking plate is centrallyI bored and vertically groovedto provide a spline connection at 54 with' the similarly serrated lowerend portion of the screw shank. Thus, the locking plate 20 is adapted tonormally lockthe screw 40 against rotation when the screw and nutmembers are in engaging position, but as the bearing plate 26'*` movesin response to screwdriver pressure as explained hereinabove and pullsthe locking disc 20 downwardly therewith' away from geared relation withrespect to the threaded portion 54 of the screw 40, the screw 40 isthereby freed to be rotated by the operator of the screwdriver forthreading of the screw relative to th'e nut i4. Upon subsequent releaseof screwdriverpressure Will immediately raise the pin and the lockingdisc 20 into locking engagement with respect to the screw spline portion54, whereby the device will again be automatically locked.

Thus, it will be understood that the fastener of the invention includesa nut and a screw Ymember arranged to be separately fastened to sheetmetal elements or the like in such manner that the nut member is rigidlymounted while the screw member is freely rotatable upon its mountingelement. 'Ihe nut member carries a locking plate which is slidable'axially of th'e direction of screw threading relative movement betweenthe screw member and the nut member, but it is xed against rotationabout said axis. The locking plate is` centrally bored and serrated toengage the similarly serrated shank end of the screw member when broughtinto registry th'erewith. Elastic force means are arunlocks the screwspline connection, and the screw member may then be withdrawn from th'enut member by a few simple turns of the screw-- .driver tool. Thus, aparticularly positive and otherwise advantageous form of self-lockingand self-unlocking fastener device is provided, and it will beunderstood that although only one form of the invention has been shownand described in detail it will be apparent to th'ose skilled in the artthat the invention is not so limited but that various changes may bemade therein without departing from the'spirit of the invention or fromthe upper end of the pinl 50, the spring 28A ranged to normally urgethe'locking plate to move into locking engagement with respect to thescrew member whenever th'e screw member is engaged in screwthreadedrelation upon the nut member. The screw member includes a telescopicallycarried key pin which is adapted to be depressed to carry the lockingplate against th'e action of the elastic force means away from lockingengagement with respect to the screw member; and the key pin is soarranged as tobe automatically so y depressed upon insertion of ascrewdriver blade into the -slotted head portion of the screw member.' li Consequently, subsequent tot respective assemf bliesofnthe screw andnut members upon the ele-Y a mentsy to be fastened, the threaded shankportion ofthe screw member may be brought into registry with the tappedbore of the nut member and screwed thereinto by means of an ordinaryscrewdriver or ,similar tool. 'I'hroughout this operation the drivingtool maintains th'e'key pin in anti-locking position. Thus. the mountingelements are vaccurately centered and forcibly carried intormlyinterconnected 'position simply by means of a few turns of thescrewdriver tool. Then, immediately upon withdrawal of the screwdriver,the locking plate moves to spline connection position with respect tothe screw member so as to automatically lock the latter Aagainstaccidental displacement therefrom. To disconnect the fastener' device,the screwdriver tool is simply inserted into the screw head slot'whereupon the key pin automatically the scope of the appended claims.

I claim:

l. A screw fastener comprising a cylindrical retainer h'aving a tappedopening in an end wall thereof and an enlarged axially extending chamberadjacent said tapped opening, a head'- ed screw for engagement in saidtapped opening and having a reduced spline portion at its end oppositethe headed end, disc means in said chamber having a blind axial recesstherein with a spline formation for receiving the splined end of saidscrew to secure th'e two elements against relative rotation, peripheralformations on said disc and complementary longitudinally extendingformations in said chamber whereby said disc may move axially in saidchamber to and from spline-engaging position, said screw having an axialbore with reduced openingsat the opposite ends of said screw, a pin insaid bore, said pin having reduced end portions for axial movement insaid reduced openings, the medial portion of said pin preventingdisassembly of said screw and pin, spring means normally urging saiddisc toward said screw, the end of said pin adjacent said splineformation being adapted to engage in said blind recess to move said discto disengaged position'by pressure against the other end of said pin.

2. A screw fastener comprising a cylindrical retainer having a tappedopening in an end wall thereof and an enlarged axially extending chamberadjacent said tapped opening, a screw for engagement in said tappedopening and having a slotted head at one end and a reduced splineportion at its end opposite, disc means in said chamber having a blindaxial recess therein with a spline formation for receiving the splinedend of said-screw to secure the rtwo elements against relative rotation,peripheral formations on said disc and complementary longitudinallyextending formations `insaid chamber whereby said disc may move axiallyin said chamber to of said pin adjacent said splineformation beingadapted t'o engage in said blind recess to move said disc -to disengagedposition, the other end of said pin being normally yieldably disposed inthe slot in said head whereby. the insertion ofscrew driving means insaid slot disengages said spline connection.

3. A screw fastener comprising a cylindrical retainer having a tappedopening in an end wall thereof and an enlarged axially extending chamberadjacent said tapped opening, a headed screw for engagement in saidtapped opening and having a reduced spline portion at its end oppositethe headed end, disc means in said chamber having a blind axial recesstherein with a spline formation for receiving the splined end of saidscrew to secure the two elements against relative rotation, peripheralformations on said discpand complementary longitudinally extendingformations in said chamber whereby said disc may move axially in saidchamber vto and from splineengaging position, said .screw having anaxial bore with reduced openings at th'e opposite end of said screw, apin in said bore, said pin having reduced end portions for axialmovement in said reduced openings to provide for limited axial movementof said pin in said bore, the medial portion of said pin preventingdisassembly of said screw and pin, spring means normally urging saiddisc toward-said screw, the end of said pin adjacent said splineformation being adapted to engage in said blind recess to move said discto disengaged position by pressure against the other end of said pin,the latter being normally resiliently disposed in a position forengagement by a screw head engaging tool to be lmoved thereby to releasesaid spline connection preliminary to a screw turning operation.

MARviN c. HERGET.

